full-scale MBR plants - Kubota Membrane Europe

1

Design and performance of

full-scale MBR plants

treating winery wastewater effluents

in Italy and Spain

KUBOTA MEMBRANE EUROPE

IWA Winery 2009

2nd April 2009

Kubota Submerged Membrane Units

Outline

1. Kubota MBR Technology

2. Kubota MBR in European wineries

3. Design aspects

4. Performance aspects

5. Conclusion

2


0. Activities of Kubota Corporation

Wastewater treatment plant

Teshima waste melting plant

Water, Environmental,

Infrastructure related

division

KUBOTA CORPORATION

Founded in Japan, 1890

24,400 employees

Turnover: US$ 11.5 Billion

(as of March 31st 2008)

Agricultural, Industrial machineries related division


1. KUBOTA Technology: Submerged Membrane Unit®

Diffuser pipe

Membrane cartridge

Tube

Manifold

Membrane

case

Diffuser case

Solid-liquid separation equipment employedin activated sludge method. The effluent is SSfree and coliforms are significantly reduced(~log 4-5)

The membrane units can be directly installedin the aeration basin, saving tank space andrelated civil works.

Characteristics

・ Easy maintenance of the wastewater

treatment facilities

・ Space saving

・ Highly purified water quality with no SS

・ Title 22 and IMO MEPC 159(55) certified

・Complies with EU Bathing Water Directive

and WHO standards for Unlimited

Irrigation

3


2. Kubota MBR in European wineries

• 400 MBR plants in Europe from which approximately 60% are industrial (2008)

• Food and beverage industry accounts for 45% of the industrial references, the largest

contributor being Wineries (22).

• All winery references located in Italy (14) and Spain (8) since 2003


3. Design aspects

• Spanish and Italian discharge consents can be met with a wide array of technologies –

in most cases winery wastewater treatment plants (WWTP) discharged into municipal

sewerage collectors.

• Observed Spanish discharge limits were 160mg/L for COD, 40mg/L for BOD5 and 5 or

80mg/L for SS, with no mention to pathogens.

• Drivers for MBR technology in winery applications are NOT discharge quality: scarce

available space, capacity enlargement of conventional treatment plants,

minimisation of visual and odour impact, need for reduced civil engineering,

treated effluent reuse for on-site cleaning or irrigation, etc

4


3. Design aspects

CHALLENGE 1: presence of solids (i.e. seeds, filtration media, diathomea sand)

Pre-treatment

MBR plants generally do not have gravity

settling tanks,

Install a 1mm screening at the head of

works in order to avoid abrasion problems

with grape seeds circulating between the

membranes,

Avoid screen by-passes with sound

designs especially during high flow events.


3. Design aspects

CHALLENGE 2: daily and seasonal variable loads (hydraulic and organic )

Equalization / Balancing tank

• Designs in Spain were provided with 24 hours’ equalization volume at peak flow

conditions ,

• pH neutralization at the equalization tank prior to the biological treatment can

contribute to remove part of the organic load.

• Even without sludge seeding, aeration can help to reduce COD due to stripping

of volatile compounds.

5


3. Design aspects

CHALLENGE 3: nutrient deficit

Biological treatment

• High BOD5/TN and BOD5/TP ratios

• Need to dose N and P to complete biological digestion

• For WWTP MBR systems, nutrient addition is in the form of urea and

phosphoric acid, dosed at the balancing tank with either automated dosing

pumps or, more often, manually. BOD5 levels are reduced to below 25 mg/L at

the effluent.


3. Design aspects

CHALLENGE 4: membrane filtration dimensioning

Reference

Membrane area Peak Flux Average Flux

m2 m3/m2/d m3/m2/d

BV 60 0.76 0.33

DV 240 0.75 0.3

JS 240 0.80 0.3

MC 40 0.90 0.38

Average flows differ by a factor of 3

between harvesting season and low

season

Design flux is dependent on liquor

temperature, viscosity and sludge

conditions

6


3. Design aspects

Configuration 1: RETROFIT Hybrid MBR plant (40 – 140 m3/day)


3. Design aspects

Configuration 2: NEW BUILD Modular MBR plant (70 m3/day)

7


3. Design aspects

Configuration 3: NEW BUILD Buffered compact MBR plant (15m3/day)

1mm slot

screen Chemicals holding tank P transducer

Permeate pump

Flow meter

Blower



PROCESS STABILITY

Lack of nutrient dosing:

Viscous bulking as a result of sudden

increases of the organic load

Peak flow management:

Chemical cleans every 2 - 6 months with

NaOCl @ 0.5% by weight concentration.

Sparse purges:

Successful operation for extended periods

above 20g/L MLSS and long sludge ages

with estimated VSS/MLSS ratio down to

60%

8



EFFLUENT QUALITY AND REUSE

Consistently compliant with the usual discharge consents for wineries

Suitable for reuse applications. In Spain 2 plants reuse for crop irrigation, with

COD 50 – 300mg/L,

BOD5 <10mg/L

SS<2mg/L

Depending on the reuse application and local regulations it may be necessary to

provide additional safety barriers such as UV or residual chlorine disinfection.



COST TRENDS AGAINST CONVENTIONAL BIOLOGICAL SYSTEMS

Civil. MBR very cost-effective for retrofits

Energy. Higher influent concentrations help towards MBR economical viability.

Favourable “kg BOD5 removed / m2 membrane filtration area” ratio as compared

to municipal.

Sludge disposal. Less dependence on sludge settleability and more sludge

stabilization should have a positive impact on the cost of sludge conditioning,

however there were no field data available to back this up.

9



OPERATIONAL PROBLEMS

Inadequate use of equipment (diffuser flushing, membrane relaxation cycles,

silicon-based antifoaming agents, etc)

No operational feedback

No preventive maintenance (blower failure)

No requests for technical assistance

Seldom sampling and sludge characterization

Sludge bulking due to:

• deficient pH adjustment due to dirty electrodes,

• wrong nutrient dosing,

• shock load due to equalization tank level kept

too low.



MEMBRANE REPLACEMENT RATES

Up to today:

1.6%. total replacement of Kubota cartridges for the European winery industry

Only one winery had required membrane replacements due to improper use of

foaming control agents which caused irreversible damages on the membrane

surface.

USUALLY: Full permeability recovery is achieved after physical and chemical

cleaning

10


5. Conclusion

Kubota membranes for MBR have been successfully applied in 22 European

winery wastewater treatment plants since 2003.

Experience shows MBR as a reliable solution for the wine industry

Easy retrofit to existing plants,

Flexibility against seasonality,

Process stability,

High effluent quality and possibility to reuse the treated effluent.

Main operational problems are identified and considered avoidable

Kubota’s membrane replacement rate across the European wineries was less

than 2% of the total installed today.


Kubota Membrane Europe

3rd floor, No.1 Farriers Yard

77 Fulham Palace Road

London W6 8AH

United Kingdom

Tel:+44(0)20 87 41 52 62

Fax:+44(0)20 85 63 16 16

http://www.kubota-mbr.com

GRAZIE MILLE!!

full-scale MBR plants - Kubota Membrane Europe

Documents

Transcript of full-scale MBR plants - Kubota Membrane Europe